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Call No. 55 \ "M / ,V^ 6, Accession No. 
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This book should be returned on or before the date last marked below. 




Glacier Variations and Climatic 
Fluctuations 

BY 

H. W:SON AHLMANN 



SERIES THREE 



THE AMERICAN GEOGRAPHICAL SOCIETY 
NEW YORK 1953 



BOWMAN MEMORIAL LECTURES 

Series One. Geography, Justice, and Politics at the Paris Conference of 
1919. By Charles Seymour. 1951 

Series Two. Agricultural Origins and Dispersals. By Carl O. Sauer. 1952 



Copyright, 1953 

by the 
American Geographical Society 



George Grady Press, New York 



Foreword 



THE THIRD in the series of the Isaiah Bowman Memorial 
Fund lectures was delivered by His Excellency Hans 
W:son Ahlmann on August 13, 1952, as the principal ad- 
dress at the meeting of the Seventeenth International Geo- 
graphical Congress in Washington, D. C. The original 
text of "Glacier Variations and Climatic Fluctuations" 
has been augmented for publication by additional data 
and references to serve as a summary of the author's latest 
thinking on the subject. It brings together the findings 
of the human and physical geographer, the geomorphol- 
ogist, the climatologist and even the historian. Dr. Ahl- 
mann has been Professor of Geography at the University 
of Stockholm, and from 1948 to 1951 served as President 
of the Commission on Snow and Ice of the International 
Association of Hydrology (I.U.G.G.). 

Dr. Ahlmann, now serving his country as Sweden's 
Ambassador to Norway, has for two decades been the 
leader in the work of relating changes in glaciers to 
climatic fluctuations. His concept of the need for collabo- 
ration between sciences the team approach and the ne- 
cessity for initiating detailed observations to achieve a 
better understanding of glacier regimen has changed the 
whole scope of glaciology. He has pioneered in developing 
methods for making precise measurements of accumula- 
tion and wastage from which to determine a glacier's econ- 
omy or hydrologic balance. These techniques not only 
provide means of learning more about glaciers themselves, 



but also make possible a much more accurate and satis- 
factory interpretation of their response to meteorological 
factors and other external influences. 

Dr. Ahlmann's studies began in Norway in 1918, were 
extended to Spitsbergen in 1931, to Iceland in 1936, and 
to northeast Greenland in 1939. The Norwegian-British- 
Swedish Antarctic Expedition, 1949-1952, was largely a 
product of his planning and organization. In the summer 
of 1952, following the meeting in Washington, he made 
a brief visit to Southeastern Alaska under the auspices of 
the American Geographical Society, supported by funds 
generously provided by the Office of Naval Research. His 
objective was to observe the principal glaciological fea- 
tures of that area and to evaluate the studies being made 
there by this Society and others, in order to further the 
development of a well-integrated international program 
of glaciological-climatological research. 

We may appropriately recall the Foreword he wrote in 
the first issue of the Journal of Glaciology, January, 1947 
(p. 3): "As a science glaciology is young, even though snow, 
ice and glaciers have been noticed for centuries . . . but 
they have been remarkably late in becoming the subject of 
systematic investigation. And this in spite of the fact that 
snow and ice are of great practical importance in northern 
countries. . . . We are as yet only on the threshold of the 
world of ice in the Antarctic that conceals the answer to 
questions of the greatest importance to the understanding 
of physical-geographical conditions both at the present 
time and during the Ice Age. The glaciers at all latitudes 
round the earth are of no less interest. As yet we know very 
little about the meteorological reasons for their existence 
and variations in size, about their structure, movement and 

[iv] 



other features. . . . The tasks confronting us are immense 
and various ..." In this volume, as in his many other writ- 
ings, Dr. Ahlmann clearly points the way to the future 
development of glaciology in both its practical and theo- 
retical aspects, especially as it may contribute to the study 
of climatic change. 

W. O. FIELD, JR. 



[v] 



Glacier Variations and Climatic 
Fluctuations 



I REGARD it as a very great honor to have been asked to 
give this lecture in memory of Isaiah Bowman, a man 
whose attainments as a scientist I have long appreciated 
through his writings and whom I had the pleasure to know 
personally, not only as a man of great distinction and a 
citizen of the United States, but as a citizen of the world. 

As the subject of my lecture I have selected a chapter in 
climatology. This science is of importance not only to 
glaciologists; it affects the whole social and economic life of 
mankind. Isaiah Bowman was much interested in climate 
and its changes. In studies of the pioneering process, for 
instance, he gave full recognition to climate as a critical 
element. He often cited the early Norse settlement of 
Greenland as an experiment on the "verge of the possible/' 
where even a slight climatic change brought disaster. 1 And 
he stressed the need of quantitative study. He himself "car- 
ried out measurements on physical indications of climatic 
change on tree rings and on strandlines in Great Basin 
lakes and later he prompted the National Academy of 
Sciences to undertake cyclic-change studies in weather and 
climate." 2 Glaciers and glaciation were a subject of special 
attention in his field work in the Peruvian Andes. 

Of recent years, glaciers have been the object of intense 
scientific research. That research, moreover, is differenti- 
ated by today's cooperation between various scientific dis- 



ciplines whereby many new aspects of a more profound 
geophysical nature have been opened up. To take one ex- 
ample, it is only within the last 20 years that any close 
attention has been given to the glacier ice itself. 3 The 
earlier unconcern has run through the whole course of 
polar exploration; it applies particularly to Antarctica, 
with 99 per cent of its area ice covered. 

Today we have a better appreciation of the necessity for 
more intimate knowledge of present-day glaciers if we are 
ever to understand Pleistocene glaciation. Richard Foster 
Flint's "Glacial Geology and the Pleistocene Epoch/' pub- 
lished in 1947, is one of the first comprehensive works to 
use glaciology as a basis for study of this period. His ap- 
proach became feasible only as a result of the recent rapid 
advance in glacier study. 

Our extraordinary technical progress has made it pos- 
sible to achieve results in practically all branches of science 
that no one would have dreamed of only a few decades ago. 
Such, for instance, in the field of polar research, is the 
determination by the seismic reflection method of the 
depths of the inland ice plateaus of Greenland and Ant- 
arctica. In Greenland this has been carried out by the 
French Polar Missions of Paul-Emile Victor, 4 and in the 
Antarctic by the Norwegian-British-Swedish Expedition 
to Queen Maud Land, 1 949- 195 2. 5 

SOME PRELIMINARY GLACIOLOGICAL RESULTS 
FROM QUEEN MAUD LAND 

Figure i, reproduced with the permission of Gordon 
Robin of the Queen Maud Land expedition, gives the re- 
sult of his seismic depth measurements from 71 S. to 74 

[2] 



30' S. It reveals a wild alpine topography covered with ice 
to a depth of up to 2500 meters an immense mass. On the 
basis of the French results in Greenland, Andre Cailleux 6 
is quite right in saying that previous estimates of the 
world's existing glacier ice are too small. He calculates that 
the total volume of land ice must be between 26 and 36 
million cubic kilometers. Melting of this volume of ice 
would raise the sea level by some 65 to 90 meters. Even 
after making allowance for isostatic adjustments, the rise 
would be from 43 to 60 meters. Now, as a result of the work 
in the Antarctic, we can say that the higher figure, 60 
meters, is probably a minimum value. 

I should like to mention here some other results of 
general interest from the Queen Maud Land expedition. 
V. Schytt's measurements at Maudheim show that temper- 
atures in the inland ice and in the shelf ice below the level 
to which the seasonal fluctuations penetrate (below about 
20 meters) correspond to the local mean air temperatures. 
Thus we have a method of determining this very important 
climatological element in a given place on the ice, even 
though we can only stay there for a day or two. Near the 
southern end of the profile in Figure i, at 2700 meters 
above sea level, the average temperature for the year has 
been calculated in this manner to be about -40 C. Temp- 
eratures below -50 C. must be common in the winter 
months. 

The possibility of traveling over the Antarctic and the 
Greenland icecaps with mechanical snow vehicles may 
soon bring us to the day when we shall know the average 
air temperature over the inner parts of these regions. Aside 
from the value of such information to regional geography, 
we can reasonably expect that the results obtained may 

[3] 



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serve as a basis for increased knowledge of the climate on 
and around the masses of Pleistocene inland icein other 
words, of the climate during the Ice Age. Present-day 
knowledge about the great ice sheets of the past is ex- 
tremely limited. I am still convinced that at least most 
parts of the Pleistocene ice sheets were of polar and not of 
temperate type, that is to say their temperatures were be- 
low the freezing point to a depth of at least a couple of 
hundred meters, with the upper score or more consisting 
of frozen snow, firn, not ice. 7 Schytt's geophysical and crys- 
tallographic analysis of a loo-meter-long core at Maud- 
heim has shown that there was no real glacier ice at lesser 
depths than Go meters. 

FACTORS INFLUENCING GLACIER VARIATIONS 

Glaciers, being conditioned by climatological factors, 
register by their variations fluctuations and changes of cli- 
mate. Even the present climates of the world are not stable 
as was once believed by meteorologists, among them the 
great Hann. They are, and always have been, subject to 
fluctuations and changes over both long and short periods. 
The scope of this field of research is so vast that I must limit 
myself to the Scandinavian countries and Iceland, with 
some comparisons from North America. 

The relations between glaciers and climate are highly 
complicated and still far from clear. Until we have solved 
the problems of the existence and the variation in size of 
glaciers, their structure, movement, and other features, we 
cannot fully utilize them as the climatological registers 
they really are. Robert Sharp 8 correctly says that accumula- 
tion is the life blood of a glacier and that "its state of health 

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can best be defined in terms of the relation between accu- 
mulation and wastage." Ablation, or wasting (melting and 
evaporation), is the crux of the matter. It seems as if abla- 
tion is at least as important as accumulation in this appar- 
ently simple relation. But it is only recently that attention 
has been turned to the question of which meteorological 
factors determine ablation in different regions. 

The basic work in this subject was carried out in 1934 
by H. U. Sverdrup on Isachsen's Plateau, a vast snow- 
covered transection glacier in Spitsbergen. 9 It was con- 
tinued on the Karsa Glacier, a small cirque or valley glacier 
in Swedish Lapland, by C. C. Wallen in 1942-1 948. 10 From 
Wallen's recent review of the most conclusive results," the 
following can be summarized. The relative importance of 
the climatic elements determining the "health of the gla- 
cier" varies from one region to another. As a rule we have 
to take into account: ( i ) the amount of the annual precipi- 
tation in solid form; (2) the temperature during that 
period of the year when it is above the melting point; (3) 
the length of that period; (4) the amount of incoming and 
outgoing radiation, both being influenced by the degree 
of cloudiness; (5) the wind velocity; (6) the humidity. 

The relative importance of the different factors gradu- 
ally changes from the beginning of the ablation season to 
its end. The influence of radiation diminishes from early 
July onwards. Its effect also depends on the nature of the 
surface, whether snow or ice, for ice has a smaller albedo 
than snow. 

In spite of differences in latitude and local conditions, 
the most important factors in the ablation process are 
shown to be convection (heat received from the air) and 
radiation. Condensation plays a much smaller part, evapo- 

[7] 



ration a still lesser. It seems that the importance of radia- 
tion increases with decreasing latitude. Table I is repro- 
duced from Wallen's report. 

The more maritime and humid the climate the more 
important in the process is convection. Vatnajokull in Ice- 
land is a good example of a glacier where ablation takes 
place under these conditions and where convection plays 
a much more important part than radiation. 12 On the other 
hand, in Peary Land in northernmost Greenland, where 
the climate is extremely continental and arid, evaporation 
from the icecap is the most important factor in the ablation 
process. 13 

Our present knowledge of glacier variations is mainly 
based on observations of their size and especially of their 
marginal variation. But the variations are primarily a con- 
sequence of the thickening and thinning of glaciers, in 
other words, of changes in volume. 

These latter changes are far more difficult and trouble- 
some to determine than the oscillations of the termini. 
Here an important question is: When does a glacier front 
react and, by advancing or retreating, affect its "health"? 
A small glacier will naturally react sooner than a large one. 
The rate of reaction is dependent also on the topography. 
If the gradient is steep or the depth great the glacier will 
move rapidly and the changes will be transmitted to the 
terminus more quickly than if the slope is gentle or the 
thickness small. Advances and retreats will therefore 
usually begin and end at different times, even in the same 
region. There is also a difference between glaciers termina- 
ting on land and in water, especially if the glacier tongue 
is afloat. The importance of calving is to be considered and 
the fact that the rate of movement of the glacier increases 
towards the ice cliff. 14 

[8] 



In the polar regions we must distinguish between the 
main inland ice masses on the one hand and on the other 
their outlet glaciers and local glaciers of different types. 

Because of the very great area of the inland ice in the 
Antarctic and in Greenland it is difficult to obtain measure- 
ments that are either representative or accurate enough to 
lead to any certain conclusion about the ice regime; that 
is to say, whether the total volume is increasing or decreas- 
ing. The Antarctic inland ice is largely surrounded by 
floating shelf ice, the extension of which is dependent on 
other factors than those of climate and glacial regime alone. 
In relation to the whole Antarctic inland ice and the main 
body of the Greenland inland ice, we must also bear in 
mind that the reaction to changes of climate is very slow. 
The Antarctic "cold center" especially offers strong re- 
sistance to external forces. In both these parts of the world 
the summer temperature is so low that a rise of a few de- 
grees may not bring the temperature above the melting 
point, and thus affect the ablation. Variations in the posi- 
tions of the termini of outlet glaciers from inland-ice 
masses are related to the supply of ice as it was determined 
by climatic conditions of a long time before. 

In a short preliminary review of the scientific work of 
the Norwegian-British-Swedish Expedition, E. F. Roots 15 
points out that "the lag between climatic change and 
change in form of the glacier may be longer than the period 
of climatic change itself " and that the Antarctic icecap is 
one great accumulation area. He adds: "A further possi- 
bility is that the thickness of the Antarctic ice-cap is not 
dependent on climatic conditions at all, provided there is 
sufficient snow accumulation to develop an equilibrium 
cross-section determined by the physical properties of ice 
and the resistance offered by the rock floor." 

[9] 



In recent years we have gained knowledge of some 
special types of high-polar glaciers. The icecaps in Peary 
Land, where evaporation is predominant among the causes 
of ablation, are characterized by Fristrup as masses of dead 
ice, which have possibly grown up under conditions of 
much greater annual accumulation and surplus in the 
regime than is the case under present conditions. The 
outlet glaciers of the inland ice are of a different type; they 
move fast and transport large quantities of ice. Glacier caps 
very similar to those found in the interior of Peary Land 
occur on Baffin, Bylot, and Devon Islands, and the south- 
ern part of Ellesmere Island. They have been described by 
Baird, 16 and are classified by him as the "Baffin Type/' 
Their nourishment is not by accumulation of firn but by 
superimposed ice from the immediate refreezing of sum- 
mer melt water. Baird has the same impression as Fristrup, 
namely that these glacier caps are relics from a climatic 
epoch of the past, one that was neither so cold nor so arid 
as the present. 

The following statement by F. E. Matthes 17 on the laws 
of ice flow is further of great importance: "Ice confined in 
a reservoir remains inert under steadily increasing pressure 
until a certain point is reached when flow sets in slowly at 
first, but increasing rapidly in velocity, even though the 
pressure remains constant or is diminished. The flow then 
continues with gradually diminishing velocity until the 
reservoir is well depleted, when the ice-mass returns to its 
inert state. The annual overflow from a glacier cirque does 
not correspond to the annual accretions; but the snow 
keeps on accumulating for several years as a rule, until 
sufficient pressure is reached to inaugurate a strong and 
rapidly accelerated forward movement. A conspicuous 

[10] 



advance of the glacier front results, which does not stop 
until the cirque is drained to a lower level/* 

In a lecture to the Norwegian Polar Club, Oslo, early 
in 1952, O. Liestol expressed the same opinion. Glaciers 
have a tendency to establish time variations of their own 
that are more or less independent of climatic factors. Over 
a long period of time a surplus may be built up in the 
accumulation area, while the lower part of the glacier con- 
currently wastes away until the frictional limit is exceeded, 
and the ice slides forward. Such a condition, he says, is 
most evident in polar and subpolar glaciers and, it may 
also be added, is especially applicable to glaciers whose ac- 
cumulation areas are situated on plateaus high above the 
valleys constituting their main ablation areas. Such are the 
Spitsbergen glaciers, which, moreover, mostly terminate 
in floating tongues in fiords. 

For the great majority of glaciers there is obviously a 
greater or lesser time lag between the beginning of a clima- 
tic fluctuation and the ensuing marginal variations. Hence 
it is very unlikely that variations in length of a glacier are 
strictly comparable with short climatic fluctuations, as, for 
example, an ii-year sun-spot period. The reactions of 
different glaciers to climatic fluctuations extending over 
considerable periods several decades or centuries may, 
on the other hand, reach their climax at about the same 
time, provided that the physical structures and morpholo- 
gy of the glaciers are not too different. 

GLACIER REGIME IN SWEDISH LAPLAND, 1941-1952 

For diagnosis of the "health of a glacier" Wallen from 
1941 to 1948 carried out systematic studies on the small 



Karsa Glacier (2 sq. km.; see PL I A). Since 1946 similar 
but more detailed investigations have been carried out by 
Schytt and Woxnerud on the Stor Glacier (3.3 sq. km.; see 
PL IB) on the highest mountain range of Sweden, Kebnek- 

TABLE II REGIME OF THE KARSA AND STOR GLACIERS 
Kdrsa Glacier (68 zo'N., 18 2o'E.; alt. 820-1440 m.) 



Budget 
Years Accumulation 


Ablation 


Def. ( ) or Def. or Sur. 
Sur. ( + ) per km. 2 


Alt. of Retreat 
Firn Line of Front 


Million cubic 


meters of water 


Meters 


Meters 


(1941-42 
1942-43 


2-3 

3-7 


3.8 
4.0 


1.5 0.8 
-0.3 -0.15 


135) \ 
1150 J 


6. 5 


1943-44 


3-9 


3-9 


o.o o.o 


1 1OO 


3.0 


1945-46 


3-5 


4-3 


0.8 0.4 


1250 


1O.O 


1947-48 


3.6 


3-2 


+0.4 +0.2 


1050 


6.0 


1948-49 


- 


- 


- 


- 


4.0 


1949-5 


- 








> 


5.0 



Total 17.0 

Mean 1942-43 
101947-48 3>/ 


19.2 2.2 
3.9 -0.2 


-i-35 

0.1 


1150 



34-5 



Stor Glacier (6y^o'N. f i8^o'E.; alt. 1080-1700 m.) 


1945-4 6 


3-5 


5-5 


2.O 


-0.6 


1480 


15 


1946-47 


3-2 


9.6 


-6.4 


-i-9 


1600 


20 


1947-48 


4-5 


4-5 


0.0 


o.o 


1450 


22 


1948-49 


6.9 


4.1 


+ 2.8 


+0.8 


1410 


H 


1949-5 


4.4 


8.4 


-4.0 


1.2 


155 


!9 


i95-5i 


2-5 


4-5 


2.0 


-0.6 


1500 


15 


1951-52 


ca. 2.7 


ca. 3.2 


ca. 0.5 


-0.15 


1460 


15 


1952-53 


4-5 

















Total 


27.7 


39-8 


12.1 


-3.6 




120 


Mean 


4.0 


5-7 


~i-7 


-0.5 


1493 


17 



[12] 



ajse. 18 The glacier regime, or material balance, is deter- 
mined for each "budget" year. A budget year begins in 
the autumn, when the accumulation first exceeds ablation 
at the firn limit; it thus extends from the first snow fall 
of winter through the ablation season of the following 
summer. 19 By regime is meant the total accumulation vol- 
ume through one accumulation season minus the net 
ablation during the following melting season, expressed 
in terms of water. 

Preliminary results from the Lapland projects are 
shown in Table II. The values for the Stor Glacier are 
based on about 10,000 measurements. 

Total accumulation and ablation have varied consider- 
ably from one year to another. On the Karsa Glacier the 
balance between them was negative three years, positive 
one year (1947-48), and balanced in one (1943-44). The 
sum total for the five budget years shows a net deficit of 
2.2 million cubic meters of water, or o.i million a square 
kilometer a year. The corresponding figures for the Stor 
Glacier were five years with negative regime, one with 
positive and one with balanced; the total deficit for these 
seven years was 12.1 million cubic meters or 0.5 a square 
kilometer a year. 

The retreat of the termini of both glaciers was con- 
tinuous and proportional to the regime. The regime of the 
Stor Glacier, it may be added, is representative of the 16 
small glaciers lying in the same massif. The highest peak of 
the Kebnekajse Range is covered by a small glacier that 
accurate measurement 20 has shown to vary in height with 
the regime of the Stor Glacier. In 1950 this highest point 
in Sweden was 2117 meters above sea level. 

It is important to note that the significance of the air 



temperature to the glacier regime is determined in par- 
ticular by its variations around freezing point. It makes no 
appreciable difference to the majority of temperate glaciers 
if the winter is more or less cold, whereas the amount of 
melting during the ablation season is of the utmost con- 
sequence. High spring and autumn temperatures prolong 
the ablation period, high summer temperatures intensify 
it. 

The negative regime, the thinning, and the retreat of 
the Stor Glacier during the seven years in which it has 
hitherto been observed, is a continuation of its behavior 
during the preceding decades. Since 1908 it has been 
characterized by recession; concurrently there has been a 
rise in the spring, summer, and especially autumn tem- 
peratures in Lapland. 

THE RECENT GLACIER RECESSION 

Most glaciers in both northern and southern hemis- 
pheres are known to have been receding more or less 
rapidly for several decades. This, "the recent glacier re- 
cession/' is exemplified by the curves (Fig. 2) showing the 
variations of glacier termini in some of the best known 
areas: Scandinavia, 21 Iceland, 22 the Alps, 23 and parts of 
North America. 24 Large glaciers have become smaller (PL 
II), small ones have disappeared completely or have be- 
come dead ice. 

I will mention some few examples from the Arctic. Most 
of the outlet glaciers of the Greenland inland ice have been 
in recession for several decades. 25 Froya Glacier (74 24' 
N., 20 50' W.) on Clavering Island in northeast Green- 
land, a local glacier with well-defined boundaries, was in- 



E 

JOOO 
1000 



200 

100 



100 
200 



SWEDEN 63N.-68N, 




Maximum extension end of 17th Century 

Maximum extension about 1910 



(E. Bergstrom) 



1675 1700 1725 1750 1775 1800 1825 1850 1875 1900 1925 1950 



B 



100 



200 : 
300 



STOR GLACIER 

Swedish Lapland 




1725 1750 1775 1800 1825 1850 1875 1900 1925 1950 



+1000 
0- 



-1000- 
-2000- 



'' f 

SOUTH NORWAY 




NIGARDSBREEN, 
(0. Liestol) 



1725 1750 1775 1800 1825 1850 1875 1WO 1925 1950 



1000 
2000 
3000 



+2000 

D 2+1000- 

| 0- 

-1000- 



+250 


-250 
-500- 
-750- 
-1000 




ICELAND, DRANGAJOKULL, 66N. 
(S. Thorarinsson) 



ICELAND, VATNAJOKULL, 64N, 
(S. Thorarinsson) 




1750/51 1800/01 1850/51 1900/01 1950/51 



SAVOIE, THE ALPS, 45N. 

(M. Mougin, 0. Liestol) 



1600 1625 1650 1675 1700 1725 1750 1775 1800 1825 1850 1875 1900 1925 1950 




ilao- 



x c\ 



T ^ 

BRITISH COLUMBI A, 50N. ' ^ 

(Mt. Garibaldi area, W. H. Mathews) S. E. ALASKA, 60N. 

(D.B. Lawrence) 



1700 1725 1750 1775 1800 1825 1850 1875 1900 1925 1950 

FIG. 2 Curves showing the variations of glacier termini. For details on construction of 
the curves see footnotes 21, 22, 23, and 24. 



vestigated in 1939-1940, the position of the snout was 
measured again in 1947 and in 1952. 26 It has continuously 
receded in a manner which may be said to be representa- 
tive of the recent glacier behavior in that part of the Arctic. 



Meters 



590 



FROYA GLACIER 



'; ' " +385 *s^_- 













^;;c^^, Terminal moraine 

---- Glacier Terminus 1939 

^^J Glacier Terminus 1952 

150+ Meters above sea level 



\\ 



FIG. 3 The snout of Froya Glacier, Northeast Greenland (74 24'N.), in 1952. 
with terminal moraines indicating its maximum extension, probably in about 
1750. The dashed line is the terminus in 1939. 

On the basis of sketch maps and photographs taken in these 
years Swithinbank concludes that the snout had receded 
75 meters between 1939 and 1947 and a further 50 meters 
up to 1952 (Fig. 3); this retreat, however, represented a 
decrease of only about 2 per cent in the total area of the 
glacier. There was a corresponding thinning of the ice even 
at altitudes well above that of the snout; for instance, at 
450 meters above sea level the glacier surface in 1952 was 
about 15 meters lower than in 1939. The active bulging 
tongue that formed the snout when the older photographs 
were taken had completely disappeared by 1952, leaving 
only a smooth, partly moraine-covered front of a type more 
characteristic of a dead ice mass. 



The Chr. Erichsen Glacier, a special high-polar type in 
Peary Land investigated by the Danish Expedition, 1947- 
1 950, and described by Fristrup, had a negative regime and 
was receding. A great part of the tableland around the 
glacier gives the impression of having been only recently 
laid bare. The Barnes Ice Cap on Baffin Island 27 showed 
a small deficit for the budget year 1949-1950, that year not 
being greatly different from the normal during the previ- 
ous decade. Photographs taken in 1934 and in 1950 show 
only a barely perceptible thinning in its lower section. 

It has already been mentioned that in Spitsbergen con- 
ditions are in many respects peculiar. A summary prepared 
for me by Liestol, points out that glacier snouts that have 
receded over a hundred years or so, suddenly begin a rapid 
advance, sometimes reaching as far as the outermost recent 
terminal moraines. Every glacier has its own period of 
variation, which is, however, dependent on the more pro- 
nounced climatic fluctuations and changes. Measurement 
of the position of the glacier terminus alone cannot give 
satisfactory knowledge of the relation between its varia- 
tions and the climate. It is necessary to investigate the 
whole glacier. The Finsterwalder Glacier in Van Keulen 
Fiord, Bell Sound, West Spitsbergen, has recently been the 
subject of comprehensive studies of the kind needed. In 
the district south of Bell Sound the total volume of ice 
in the glaciers was more or less unchanged from 1920 to 
1936. The Finsterwalder Glacier itself decreased in vol- 
ume between 1936 and 1950 and showed a strong negative 
budget in 1950-1952, mainly because of exceptionally 
scanty accumulation. 

Thorarinsson's map (Fig. 4) of two glaciers in southern 
Iceland, Breidamerkurjokull and Hrutarjokull, supple- 



ments the curve showing the oscillations of Icelandic 
glaciers (Fig. zD). The present position of the termini 
should be about the same as it was in the last part of the 




FIG. 4 The termini of Breidarmerkurjokull and Hrutarjokull in southern 
Iceland. The glacier front in 1904 (continuous line) is according to the Danish 
General Staff; position in about 1850-1890 (dotted line) is based upon the 
terminal moraines; position in 1950 (dashed line) is according to a survey by 
the Durham University Iceland Expedition. 

i7th century; they are much more advanced than in the 
time of the Sagas (A.D. 870- 1 2 64) , 28 

Before turning to North America the recent general re- 
cession of European glaciers may be noted in summary. A 
list of measured glaciers for 1 947-5 o 29 shows the following 
per cent in retreat in 1947-1948: French, 100; Swiss, 77; 



Italian, 98; Austrian, 89; Swedish and Norwegian, 97; Ice- 
landic, 88. In total, of 262 measured glaciers 88 per cent 
were in retreat, only 6.5 per cent advancing. For 1949- 
1950 the figures are: French, 93; Swiss, 99; Italian, 96; 
Austrian, 100; Swedish and Norwegian, 91; Icelandic, 67. 
In total, of 318 measured glaciers, 96 per cent were in re- 
treat, 3.5 per cent advancing, 0.5 stationary. 

Our knowledge of the oscillations of the North Ameri- 
can glaciers 30 rests partly on old descriptions and photo- 
graphs and on tree-ring studies and partly on systematic 
measurements. Conditions in different regions sometimes 
differ greatly because of morphological and other causes, 
as I have already mentioned. Moreover a large number of 
glaciers in Alaska end in fiords and are thus in the same 
class as the Spitsbergen glaciers with their anomalous 
variations. 

Reference should be made here to two important sys- 
tematic investigations the Arctic Institute of North 
America's project "Snow Cornice," located on the Seward- 
Malaspina Glacier System on both sides of the interna- 
tional boundary line in the St. Elias Mountains, and the 
Juneau Ice Field Research Project of the American Geo- 
graphical Society, supported by the Office of Naval Re- 
search. Both have as a common object to help in putting 
American glaciology on a dynamic and qualitative base. 

On the general situation D. B. Lawrence has this to 
say: 31 "The glaciers emanating from the southern part of 
the Juneau Ice Field . . . seem to have advanced in unison 
to a maximum some time in the early or middle eighteenth 
century, which surely had not been exceeded since before 
the 1 300% and from which recessions of 1.3 to 5 miles be- 
ginning by 1765 at the latest subsequently occurred. The 

[19] 



same chronology has been reported from Glacier Bay, 
Alaska, from Garibaldi Park, British Columbia, from Mt. 
Hood, Oregon, and even from Norway and Iceland/' 

In Alaska the behavior of the glaciers has been more 
heterogeneous than in most other parts of the world. 32 As 
Matthes earlier pointed out "in a region of such marked 
topographical diversity as Alaska, it is to be expected that 
some glacier basins will respond more quickly than others, 
and on a different scale, to a given change in climatic con- 
ditions/' Concerning the immense recession in Glacier 
Bay over 60 miles since the i8th century, of which 16 
have been since 1892 I am of the opinion that the most 
noteworthy fact is the advance of the glaciers in the eight- 
eenth century rather than the recession which followed. 
The climate in the lower parts of Glacier Bay district, 
where the ice has thinned out and from which it has re- 
treated, is not suited to the survival of great ice masses. 
Even during a climate more favorable to glaciers than that 
of the present time, ice transported to the lower parts of 
the region must melt away more or less rapidly. The prob- 
lem to be solved is the reason for the catastrophic advance 
of the glaciers which covered these areas with such a thick 
sheet of ice. The recession in Glacier Bay cannot be taken 
as evidence of the importance of the present climatic 
fluctuation. On the other hand, the glacier advance in the 
eighteenth century points towards the probability of there 
having been a climate favorable for glaciers during the 
preceding centuries. The present advance of Taku, while 
all other outlet glaciers of the Juneau Ice Field are reced- 
ing, has attracted attention. Perhaps Matthes' claim of "an 
upward shift of the zone of maximum snowfall" has actu- 
ally taken place in some sections of Alaska. 33 

[20] 



A summary, prepared for me by William O. Field, Jr. 
in the spring of 1 952, gives glacier variations in recent years 
in that part of North America lying south of Alaska. It 
makes clear that the rate of recession of several glaciers has 
decreased appreciably, or has even changed to an advance 
paralleled by a thickening of the ice. The turning point 
in some cases occurred about 1945.^ The renewed activity 
of these glaciers has been intensified rather than dimi- 
nished during the last two seasons (1951 and 1 952) in spite 
of their exceptional melting. The behavior of Nisqually 
Glacier and the other glaciers of the same type is dependent 
on the relation between snow and ice sources in their upper 
parts and the melting of their lower parts. 35 

Even if the times of maximum glacier extension in dif- 
ferent parts of the world have differed slightly, there is a 
striking resemblance in the general trend of variations in 
Europe and North America. Comparing the results of 
budget studies in Lapland and Alaska we find a close paral- 
lel in glacier behavior and temperature development. The 
19481949 budget year, which had a strongly positive 
regime, was clearly marked in both. The size and com- 
position of the accumulation area on the Seward Glacier 
also gives evidence of a close parallel in other years. 

And though the data from other parts of the world is 
less complete, there are nevertheless signs that the margin- 
al variations of glaciers have been more or less concurrent 
in recent centuries all over the world. 36 The ice fields on 
the large extinct volcanoes of Central Africa have dimin- 
ished greatly. 37 Old terminal moraines in front of the 
present glaciers show that they have been much larger in 
relatively recent times. From the post-glacial maximum 
extension their retreat appears to have been interrupted 

[31] 



by periods of stagnation and advance. The recession of 
some was greater after 1 930 than it was in the period 1 900- 
1930. At present, however, the Ruwenzori glaciers seem to 
be in a rather stable condition; accumulation normally ex- 
ceeds ablation, keeping them well nourished. 

More or less definite glacier retreats have been reported 
from Asia Minor, 38 South America (especially Chile 39 ), and 
also from New Zealand. 40 From the Antarctic we have 
Schytt's observations from Queen Maud Land in 1950- 
1951. They indicate that at present a state of equilibrium 
exists between nourishment and outflow of the inland ice, 
and that the ice cover has not thinned during the last 
decades. 

THE PRESENT CLIMATIC FLUCTUATION 

As to the present climatic fluctuation, I should like first 
to refer to some comprehensive studies, in particular to 
Leo Lysgaard's "Recent Climatic Fluctuations*' and H. C. 
Willett's "Temperature Trends of the Past Century." 41 
The numerical values on Figure 5 are in tenths of a degree 
Fahrenheit for the last 20 years, winter temperature 
change centered to 1930. It is of particular interest to note 
that the temperature rise has been most pronounced in 
the northern hemisphere, where it increased with the 
latitude, the rise reaching its maximum values in Spits- 
bergen (Fig. 6) and in Greenland. No counterpart is in- 
dicated in the higher latitudes of the southern hemisphere. 
We must remember, however, how scattered and tempo- 
rary the observations have been and still are in the Ant- 
arctic. Speaking generally, the difference between the sum- 



4!? 




FIG. 5 Twenty-year changes of the mean winter temperatures centered on 
1930. The numeric values in tenths of a F. (After H. C. Willett, see footnote 41). 



C 

+6 



-1-5 - 
+4 - 
+3 
+2 - 

+1 - 

o- 

-1 - 
-2 
-3- 
-4 - 



-5 



W. SPITSBERGEN 

Overlapping 10 years anomalies 
from mean value 1901-1930 




Winter 

Spring 

Summer 
Autumn 



1894- 
-1903 



1904- 
-1913 



1914- 
1923 



1924- 
1933 



Fir,. 6 Seasonal mean temperatures in West Spitsbergen (78 N.). Overlap- 
ping lo-year anomalies from the mean value 1901-30. 



[23] 



+19.0 
+18.0 
+17.0 
+16.0 
+15.0- 

8.0 
7 JO 
6.0 
5.0 
4.0 
3.0 
2.0 

0.0- 
-1.0- 
-2.0- 
-3.0- 
-4.0- 
-5.0 




STOCKHOLM 




July 



October 



April 




January 



+18.0 
+17.0- 
+16.0- 
+15.0- 

+9.0- 
+8.0- 
-J-7.0 
+6.0- 
+5.0- 
+ 4.0 

+1.0- 

0.0 

-1.0 



LUND 



July 



October 





April 



January 



+i5.a 

+14.0- 
+13.0- 
+12.0- 
+11.0- 

-1.0 
-2.0- 
-3.0- 
-4.0- 
-5.0- 

-11.0- 
-12.0- 
-13.0- 
-14.0- 
-15.0- 
-16.0 




July 



KARESUANDO 



October 





April 



January 



FIG. 7 Seasonal temperatures at Swedish stations plotted in 
lo-year overlapping means: Stockholm (59 so'N.); Lund (55 
4o'N.); Karesuando (68 2o'N.). 



mer and winter temperatures became smaller up to the 
1930*8, or in other words, up to that time the climate had 
shown a definite tendency to become more maritime. 

This is fully confirmed by the curves published by the 
late A. Labrijn 42 showing the difference between the mean 
temperature of July and that of the preceding January, in 
14 places throughout Europe, for the period from 1750 
until 1945. The same trend was clearly marked in Lenin- 
grad, Stockholm, Edinburgh, and Lancashire (England). 
Since the 1930*8 however, it has been reversed. It is worth 
noting that Paris, Prague, Vienna, and Budapest do not 
show a parallel tendency before the 1930*5 but since that 
time the reversed trend (i.e. towards a more continental 
climate) has been prominent. Moreover, most other places, 
and even subpolar regions, provide evidence that the pre- 
sent climatic improvement culminated during the 1930*5 
or 1940'$. 

Curves giving ten-year overlapping mean temperatures 
from several stations in Sweden (Fig. 7) show that the in- 
crease in winter temperatures ceased with the 1930'$ and 
was succeeded by an equally clear decrease. At some sta- 
tions the January temperatures in the latest decade are 
lower than they have been at any time since the turn of 
the century. In Stockholm they have not been lower since 
1 860. Of course the remarkably cold winters of 1 940, 1 94 1 , 
and 1942 play an important part in this decrease; yet even 
if overlapping means are calculated on the assumption that 
those winters had normal temperatures, a definite decrease 
is revealed. 

However, spring and even more autumn temperatures 
are still rising. In some parts of Sweden summer tempera^ 
tures also are rising, in other parts the maxinpiin has al- 

[35] 



ready been reached. It is particularly evident that the rise 
of summer temperatures in the glacier regions of north- 
western Scandinavia has culminated. At Karesuando and 
at Tromso (Fig. 8), for instance, July temperatures show 
continuous decrease since 1930-1939. In southern Sweden, 
in Lund and Stockholm for example, the maximum 'was 
reached only a few years ago or has not yet been reached. 
The annual mean temperature is still showing a rising 
trend. 



FIG. 8 Seasonal tem- 
perature anomalies from ^ Q 
the 1901-30 mean value 
at Tromso, Norway (66 gg 
40- N.). 

On the right lo-year 0.4 
overlapping anomalies; 
below, 3o-year overlap- Q 
ping anomalies. Notice 
the great difference be-- 0.4- 
tween the two groups of 
curves. 0-8 - 



Winter 

Spring 

Summer 

Autumn 




1899-1908 1909-1918 1919-1928 1929-1938 1939-1946 



0.8- 
0.6- 
0.4- 
0.2 
0- 
0.2 
0.4 .| 
0.6 




Winter 
Spring 
Summer 
Autumn 



0.8 

1856-1885 1866-1895 1876-1905 1876-1915 1896-1925 1906-1935 1916-1945 



[*6] 



- -* -* 




FIGS, g and 10 Overlapping 10- 
year temperature anomalies in Ice- 
land from the mean value 1901-30. 

Figure 9 (left) is for Reykjavik. (64 10' N.); Figure 10 (right) is for Grimscy 

(66 30' N.). 

At Reykjavik in Iceland (Fig. 9) the climatic improve- 
ment culminated in the 1 940*5 and was succeeded by a 
deterioration, particularly in spring and autumn tempera- 
tures. But winter and average annual temperatures are 
still much higher than they were in the years preceding 
1925-1930. The high temperatures recorded since 1890- 
1900 in all seasons at Grimsey on the north coast (Fig. 10) 
are still being maintained. 

In the United States the decade 1 94 1-1 950 seems to have 
been characterized by lower temperature and increased 
precipitation in comparison with the decade 1931-194O. 43 

From many points of view both scientific and practical 
it is thus of great importance that we should follow, care- 
fully and systematically, the climatic developments of the 
near future. This applies especially to the polar and sub- 
polar regions. 

[27] 



CAUSES OF THE RECENT GLACIER RECESSION AND 
THE PRESENT CLIMATIC FLUCTUATION 

The coincidence in time of the recent glacier recession 
and the present climatic fluctuation suggests a causal con- 
nection between them. I have come to the conclusion that 
increased ablation, consequent upon the increase in tem- 
perature, has played the fundamental role in the recession 
of glaciers around the northernmost Atlantic. I also find 
it probable that the rise in spring and autumn tempera- 
tures, i. e. the lengthening of the ablation season, has been 
of particular importance. As I have said before, 44 "The 
great shrinkage and recession of the glaciers is to a pre- 
ponderating extent due to an increased transfer of heat 
through the atmosphere by a strengthening of the winds 
carrying heat from southern parts to the Arctic." The dis- 
cussion about the meteorological causes of the present cli- 
matic fluctuation that is still going on has for the most part 
supported this general thesis. 

Twenty-five years ago Wagner explained the current 
climatic fluctuation by increased general atmospheric 
circulation with an increased exchange of heat and other 
atmospheric elements between northerly and southerly 
latitudes. 45 More recently B. E. Eriksson 46 found the most 
important feature of this fluctuation over the northern- 
most Atlantic to be a change in the pressure gradient 
causing an increased flow of warm air into northern lati- 
tudes. Willett 47 introduced the terms "high-index" and 
"low-index" to characterize two quite different types of 
circulation in the middle latitudes. With the "high-index" 
circulation cyclones move in winter in a strong zonal flow 
on fairly northern tracks from the Atlantic towards north- 
western Europe giving mild southwesterly to westerly 

[28] 



winds. The "low-index" circulation is characterized by a 
meridional flow pattern with the winter cyclonic tracks 
shifted southward giving cold easterly and northeasterly 
winds over most of Europe. However, Petterssen 48 has 
shown that "a warming up of northern latitudes in winter 
during the 1930*5 has been connected with a development 
towards another type of 'low-index' circulation pattern 
where the zonal components are also weak and the north- 
south components dominate." Instead of an increased zonal 
flow over northwestern Europe there has been a more 
meridional type of flow pattern giving rise to an increase 
in the northward transport of air from southern and east- 
ern Central Europe towards Scandinavia; and simultane- 
ously an increased northward transport of air from the 
eastern Atlantic towards Iceland and the Norwegian Sea. 

Partly in contradistinction to my own opinion is Wal- 
len's belief' 9 that the most important cause of the retreat 
of the Karsa Glacier during the last decades and probably 
of other glaciers in Scandinavia has been the rise of the 
summer temperature, 50 with prolongation of the ablation 
season of secondary importance. Wallen says: 51 "The es- 
sential cause for the regression and shrinkage in recent 
decades has been the increase for the heat supply from the 
air conveyed by convectional, conductional and conden- 
sational processes . . . there has also been a definite rise in 
the moisture content of the air ... and it is likely that 
the average wind-velocity has increased." In an article in 
preparation Wallen shows that the increase of southerly 
winds towards northern Scandinavia and the Arctic during 
the last 40 years is true not only for winter, as Petterssen 
pointed out, but also for summer. Referring to Petterssen's 
interpretation he concludes: "The increased general circu- 

[29] 



lation in recent decades has given rise to an increased ex- 
change of air between north and south over the Atlantic- 
European sector of the hemisphere. Both in winter and 
summer there has been an increased frequency of winds 
with a southerly component with a corresponding increase 
in temperature, humidity and cloudiness but giving no 
appreciable increase in winter precipitation." 

The "blocking-action" over western Europe 52 which has 
occurred quite often during recent decades and which has 
given rise to warm southerly and southwesterly winds over 
Scandinavia may well have contributed to glacier retreat. 

The opinion seems to be gaining ground among meteor- 
ologists that both brief fluctuations and long-range changes 
of climate, including the Pleistocene glaciations, are of the 
same general character and are ultimately dependent upon 
solar variations. In an article on the general circulation of 
the atmosphere Petterssen 53 points out "that the radiative 
processes, in tending to establish radiative equilibrium, 
create dynamic instability which gives rise to meridional 
circulations that contribute to the exchange of heat and 
atmospheric properties." He emphasizes the importance 
of mountain ranges, inland water bodies, etc. in the forma- 
tion of local circulation systems. A large-scale statistical 
analysis of the behavior patterns of cyclones and anti- 
cyclones in the northern hemisphere during the period 
1 899- 1939 shows agreement between his theoretical re- 
sults and existing conditions, thereby giving scientific sup- 
port to the old ideas of the importance of mountain chains 
and orographically active epochs to the climate in past 
ages. 54 

Petterssen's circulation models for the lower part of the 
troposphere in the northern hemisphere reveal an even 

[30] 



greater similarity in the dynamic-meteorological and 
climatological character between Alaska and western 
Scandinavia than has been presumed earlier. D. E. Martin, 
in an unpublished communication, confirms this by show- 
ing that positive and negative anomalies of the 700 milli- 
bar surface over Scandinavia are more directly related to 
similar anomalies in the Alaskan-Aleutian region than 
they are to anomalies elsewhere. 

Willett in his study of temperature trends has gone a 
step further. He maintains that changes in the ultraviolet 
part of the solar spectrum are not only causing the present 
climatic fluctuation but have also caused the great and 
small climatic changes of the past. Time will show whether 
his theory survives better than its predecessors. His idea 
has the advantage over most others in that the ultraviolet 
solar radiation varies more than the total radiation of 
energy. According to Willett, the present amelioration of 
the climate has now come to an end, and the temperature 
will fall for the next i o or 15 years, reaching a minimum 
between 1960 and 1965. 

Whatever the future may bring, we are justified in say- 
ing that of the endless series of climatic fluctuations that 
have occurred from the beginning of the earth and that 
will continue in the future, the present one is the first that 
we can measure, investigate, and possibly explain. 

CHANGES IN ARCTIC DRIFT ICE AND IN ANIMAL 
AND PLANT LIFE 

The thickness of the ice forming annually in the North 
Polar Sea has diminished from an average of 365 centi- 
meters at the time of Nansen's Fram expedition of 1893- 



96 to 218 centimeters during the drift of the Russian 
icebreaker Sedov in 1937-40. The extent of drift ice in 
Arctic waters has also diminished considerably in the last 
decades. According to information received in theU.S.S.R. 
in 1945, the area of drift ice in the Russian sector of the 
Arctic was reduced by no less than 1,000,000 square kilo- 
meters between 1924 and 1944. The shipping season in 
West Spitsbergen has lengthened from three months at the 
beginning of this century to about seven months at the 
beginning of the 1940'$. The Northern Sea Route, the 
North-East Passage, could never have been put into regular 
usage if the ice conditions in recent years had been as 
difficult as they were during the first decades of this 
century. 

The same influences that have affected the drift ice have 
affected the animal life of the North Polar Sea. Various 
kinds of fish, especially cod, have migrated northwards. 
Now for the first time cod is available to many Greenland 
Eskimos who previously had to rely on seal for food. 55 In 
a speech five years ago the Danish Prime Minister said: 
"In the last generation changes that have had a decisive 
influence on all social life have occurred in Greenland. A 
new era has begun. These changes are primarily due to 
two circumstances. Firstly, the Greenland climate has 
changed, and with it Greenland's natural and economic 
prospects/' 55 

On the other hand, herring catches off the north coast of 
Iceland have greatly diminished in the last seven years, 
possibly because of changes in the sea currents connected 
with the present climatic fluctuation. Herring has become 
an open sea fishery; its 1952 season was extended to No- 
vember instead of ending as usual in August. 

[3*] 



It is such phenomena that caused the International 
Council for the Exploration of the Sea to adopt the follow- 
ing resolution at its meeting in Denmark in 1948: "Having 
considered a number of lectures on climatic fluctuations, 
the Council recommends that these important and far- 
reaching problems ought to be more closely investigated, 
and that these investigations might be adequately sup- 
ported by the Governments in the different countries." 57 

Many land animals in northern Europe and Asia are 
now ranging farther north than before. The migration 
seems to have begun slowly at the end of the eighteenth 
century, but has been greatly accelerated since 1910. Birds 
in particular have reacted quickly and markedly to the 
present climatic fluctuation. According to a report I have 
recently received from C. Edelstam of Stockholm, careful 
observation shows that about 25 per cent of all North- 
European bird species have taken part in this movement. 
The causes are two-fold: throughout the northern regions 
winters have been milder and springs warmer. At the same 
time lakes and bird-feeding grounds in large parts of Africa 
and southwest Asia have dried up. As a result, southern 
species dependent on shallow eutrophic waters are strongly 
represented in the migration. 

Effects of the present climate fluctuation are seen to 
advantage in Finland, a country of marginal location. On 
the initiative of I. Hustich, the Geographical Society of 
Finland has just published a symposium on the phenome- 
na, 58 studied from a biological and biogeographical point 
of view and embracing effects on forestry, agriculture, fish- 
ing, and hunting. 

In the first place, it has been observed that the freezing 
period in the Baltic decreased during the 1 20 years before 

[33] 



the 1930*8, after which a return to a longer freezing period 
began. This later climatic deterioration culminated in the 
beginning of the 1 940*5. Since then there has been a rise 
in winter temperature, resulting in a longer navigation 
period. 59 

Floristically there has been a distinct shift towards 
earlier flowering and earlier ripening of berries and other 
seeds, and towards later defoliation. Ranges of plants and 
trees have expanded northwards, with attendant disturb- 
ance of species equilibrium in the plant communities. 

Effects on the coniferous forests are of particular in- 
terest. Between 1910 and 1920 the average annual ring 
index increased in all parts of Finland, especially in north- 
ern districts. Analyses of annual rings, which date back over 
200 years, show scarcely any other period as favorable as 
the 1920*8. The significance of the change in climate, par- 
ticularly of the higher temperatures, is even more clearly 
indicated by the northern timber line. About 40 years ago 
the outlook for the northernmost pine forests was rather 
poor, as there had been no seed years there since 1850. 
Now, almost all age classes are represented in the seedling 
stands (PL III A). 

Hustich himself shows the importance of the climatic 
factor in the increase in the yield of rye, the commonest 
cereal, in the period 1921-1939. 

Birds have reacted in the same general manner noted 
for northern Europe as a whole. In Finland many species 
of mainly northern distribution have become scarcer at 
their southern limits, and the accidental species found in 
1880-1941 have mainly been newcomers from the south. 

Contributions from other countries have been limited 
to specialized studies and scattered observations. I think, 

[34] 



however, that in Sweden and Norway the effects may on 
the whole be said to be similar to those in Finland. A 
critical analysis of the very extensive Swedish material on 
annual rings in pine and spruce, though not yet complete, 
justifies the statement that the present climatic fluctuation 
with its consequent prolongation of the growing season 
has probably helped towards the gradually increasing 
yield of the Swedish forest, as B. Eklund of the State In- 
stitute of Forestry Research has described in correspond- 
ence with me. 

Changes in the vegetation, as in Finland, are more 
marked in the far north, for instance, in the Abisko Na- 
tional Park (68 20' N.), undoubtedly because there the 
temperature has on the average risen more than in south- 
ern Sweden. Peat hummocks containing ice, the so-called 
Raises, a typical subpolar phenomenon, have been de- 
stroyed by melting of the ice. 60 The timber line for moun- 
tain birch has risen about 20 meters during the last decades 
and the surrounding vegetation has extended and become 
much richer (PL IV), especially during the 1940*5; partly, 
it seems, because of the earlier disappearance of the snow 
cover and the quicker drying of the soil. Sparse pine stands 
that formerly averaged only one new generation a century 
have added several new generations since the 1920*5. Dur- 
ing the iggo's in particular, regeneration was unusually 
rapid. 60 

An investigation into the water economy of eight catch- 
ment areas in various parts of Sweden from 1920 to 1947 
shows that evaporation has increased markedly since about 
ig 3 o. 61 

In most parts of Norway, as in Sweden, the timber line 
has risen during the last decades. Among the several causes 

[35] 



are the reduction or discontinuance of lumbering in the 
uppermost parts of the birch and coniferous belts and the 
reduction of grazing and reindeer keeping. All students of 
the problem agree, however, that an improving climate has 
played an important part in accentuating the consequences 
of such cultural conditions, most especially in northern 
Norway. 62 

In a recent communication, R. Sognen, of the Nor- 
wegian Watercourse and Electricity Board, points to an 
unfortunate effect that might follow continuance of the 
present trend. Continued and rapid recession of glaciers 
might prove fatal to some of the Norwegian power genera- 
ting stations, for it would reduce the quantity of water 
which the ice has stored for centuries and upon which the 
stations partly depend for their supply. 

The present climatic fluctuation has been even more 
marked in Iceland than in the other Nordic countries and 
its influence on local plant and animal life is perhaps more 
apparent than in any other region. A few of the current and 
still continuing changes may be noted: The peat and ice 
hummocks, rusts, (same type as the poises of Lapland), 
which characterize the marshes, fids, in the interior of Ice- 
land (PL III B), are gradually disappearing under the 
milder climate. The whole landscape, in fact, is changing. 63 
There has been a rise in the lower fid limit; it corresponds 
with the northward recession of the southern limit of the 
Siberian permafrost zone. In this connection, attention 
may also be drawn to the so-called "oriented lakes" 64 of 
northernmost North America created by melting of the 
permafrost. 

Because of Iceland's geographical position, elements of 
both southern and arctic faunas live there under peripher- 

[36] 



al conditions and react quickly to climatic changes. Seven 
new southern species of birds have begun breeding in Ice- 
land within the last 50-60 years, there has been a consider- 
able increase in the wintering of partly non-migratory 
species, and there has been a very noticeable increase in 
winter visitors and vagrants from the south. No less than 
37 new species or subspecies of birds have been added to 
the Icelandic list since 1938, and at the same time some of 
the few arctic and high-arctic species have disappeared. 65 

THE PRESENT CHANGE IN THE SEQUENCE 
OF CHANGES 

How then do the present climatic fluctuation and the 
recent glacier recession compare with conditions in earlier 
centuries and millenia? How do they fit into the progres- 
sion since the melting of the Pleistocene glaciers? 

The two curves of Figure 1 1 are plotted to illustrate our 
present conception of the sequence in Sweden 66 and Nor- 
way 67 from about 8000 B.C. to 1950 A.D. The glacier-varia- 
tion scale is relative and the time scale logarithmic, in order 
to show clearly the recent centuries and decades of time, 
which are, of course, the best known. The third, dashed 
curve, gives the position of the firn or climatic snow line 
on Vatnajokull, Iceland, according to Eythorsson. 68 

In the lake district of south Sweden, and within the 
present coastal region of Norway, the waning inland ice 
re-expanded in about 8000 B.C. It subsequently retreated 
under the improving climatic conditions. The economic 
regime of the Ice Age, which year after year provided a 
surplus of snow, had long since been abandoned. The rest 
of its immense capital of ice was consumed by a milder 

[37] 



regime, more favorable to mankind. The Climatic Opti- 
mum occurred between about 7000 B. C. and about 1000 
B. C. In that epoch the firn line of Vatnajokull is estimated 
to have been at about 1400 meters above sea level. Studies 



wieiers 
3500 


k k 




3000- 


xBothnian glacial substage 
(End moraines) 




2500- 




GLACIER VARIATIONS, SWEDEN 


Meters 
above 


2000- 




(E. Bergstrom) 
Climatic 
Optimum 


sea level 








-1400 


1500- 






1200 








-1000 


1000- 






800 


500- 
0- 




_y ^ v -~-^_ 


600 


v/v/ 



8000 5000 



1000 



1000 



1600 1750 



1900 



1950 



GLACIER VARIATIONS, NORWAY (O. Liestol) 



v FIRN LINE, VATNAJOKULL, ICELAND 




8000 5000 



1000 



1000 



1600 1750 



1900 



1950 



FIG. 11 The recession of the last Pleistocene inland ice from Sweden 
and Norway and the variations of the local Scandinavian glaciers during 
the last 12,000 years. For sources see footnotes 66 and 67. 

of peat bogs in Sweden have shown that there were prob- 
ably changes, in atmospheric humidity at least, in about 
2300 and 1200 B.C. The subsequent deterioration of the 
climate culminated in about 500 B.C. and the firn line of 
Vatnajokull dropped to 500-600 meters. That climate 
still exists even if it has improved somewhat during certain 

[38] 



times. There is no evidence in either Sweden or Norway 
of any glacier variations or climatic changes during the 
following 2000 years, except in the favorable Roman 
period (A.D. 0-400). We know, however, as has been 
mentioned before that from the first colonization of Ice- 
land in A.D. 870 until about A.D. 1200 the glaciers were 
much smaller than they are now. The Vatnajokull firn line 
is calculated as having been at about 1 100 meters at that 
time. From the latter part of the i7th century right up 
until the latter part of the i gth and the beginning of the 
soth century, glaciers both in Iceland and on the con- 
tinent of Europe were more extensive than at any time 
since the melting of the last remnants of the Pleistocene 
inland ice in the Scandinavian mountains. The Vatna- 
jokull firn line dropped to its minimum. The recent gla- 
cier recession, which began earlier in some districts and 
later in others, has in the last few decades reduced the 
glaciers so much that they are now probably as small or 
even smaller than they were in Roman time. The Vatna- 
jokull firn line has risen successively to its present altitude 
of about 1 100 meters above sea level. 

Thorarinsson's studies of the past and present cultiva- 
tion of cereals in Iceland have shown that in recent years 
climate there has been at least as favorable, and probably 
even slightly milder than it was in the centuries imme- 
diately after A.D. goo, and it is warmer now than at any 
time since isoo. 69 According to Thorarinsson, the ampli- 
tude of the climatic fluctuation in Iceland has in all proba- 
bility been greater since the i88o's than at any time since 
about 600 B.C. 

It has already been pointed out (p. 18) that the present 
position of the termini of some glaciers in southern Ice- 

[39] 



land ought to be about the same as in the last part of the 
seventeenth century. They are however much more ad- 
vanced than in the time of the Sagas (A.D. 870-1264). The 
position of the farms Fjall and Breida (Fig. 4) is not known 
exactly but must have been close to that shown. They 
were probably built around A.D. 900, and cannot at that 
time have been in a dangerous position to a glacier front 
or to drainage of ice-dammed lakes. Yet Fjall was aban- 
doned in 1695 and buried by the glacier in 1708. Breidd 
was a large farm until the fourteenth century, but in 1698 
it also was abandoned and in 1702 the glacier front had 
almost reached it. Thorarinsson points out that the de- 
cline of Breida is not only a result of the deterioration of 
the climate but also largely of the eruption of the volcano 
Oraefijokull in about 1360. It seems, he says, that this cli- 
matic deterioration had already begun in the thirteenth 
century, accelerated in the fourteenth, and culminated 
during the seventeenth to nineteenth centuries. 

These conclusions from Iceland agree with some con- 
clusions from Greenland. It is hardly possible that the 
climate of southwest Greenland could have been so severe 
when the Norse colony there was an independent society 
with about 300 farmsteads, 3000 people, and a surprisingly 
large number of cattle and sheep, as it was some decades 
later. 70 In 1921 excavations of the cemetery at Herjolfsnes 
yielded well-preserved clothing from about the year i4oo. 71 
Interment must have been in loose earth but preservation 
was possible because the ground was frozen soon after the 
interment. 72 

Concerning the Alps, Kinzl 73 has come to the conclusion 
that the glacier advance of the last 300 years is the greatest 
that has occurred since the Pleistocene Ice Age. "Those 

[40] 



300 years therefore/' says Matthes, 74 * 'comprise a separate 
epoch of glacier expansion, a lesser ice age, that was pre- 
ceded by a warm period of considerable duration/' It is 
worth while reflecting that our modern machine culture 
was born and has grown up under climatic conditions even 
more unfavorable, certainly, than those which extended 
since Celtic time, i.e., since the Persian wars and Classical 
Greek time. 

In large areas of North America, as has been mentioned 
before, a strong glacier advance attained its maximum in 
the first half of the i8th century. It also was the maximum 
state of advance since the twelfth century. 

Matthes has characterized the period of the last 4000 
years as "the little ice age/' I am more inclined to say: 
Regeneration of the glaciers began in about 500 B.C.; after 
some centuries of rapid increase growth was slower until 
the thirteenth or fourteenth centuries when it again accel- 
erated and so far has reached its climax in most districts 
between the first half of the eighteenth century and about 
1900. 

However, in front of some glaciers, for example some of 
Vatnajokull and Myrdalsjokull in Iceland, there are ter- 
minal moraines which might indicate that in early "sub- 
atlantic" time (the first centuries about the beginning of 
our era) these glaciers advanced a little further than during 
the last few centuries. 75 In front of several glaciers in the 
high mountains of Sweden there also is one morainic ridge 
just outside those representing the maximum extension 
about 1750 and much older. Similar examples occur in 
southern Norway 76 and in the central Alps. 77 



SOME ASPECTS OF THE FUTURE 

I have tried in this lecture to give you a brief outline of 
our present knowledge of recent glacier variations and the 
present climatic fluctuation, based chiefly on facts estab- 
lished in the Nordic countries and to a lesser extent in 
North America. I have also tried to project these phe- 
nomena against the background of what Scandinavian stu- 
dents consider the most likely progress of the melting of 
the inland ice and the most likely local glacier variations 
in the last 10,000 years. Our results are most certainly in- 
complete and in some, perhaps many, respects may prove 
to be erroneous. But in the treatment of these and of many 
other problems a new epoch is now opening before us. 
A few examples will suffice. 

Its new-found geophysical basis has made glaciology bet- 
ter able to explain the reactions of glaciers to meteorologi- 
cal factors. We hope to be able to organize international 
cooperation for the purpose of getting accurate values of 
representative glacier regimes for elucidating glaciological- 
climatic development in the subarctic zone. The glaciers 
ought to be not too big but should be well defined. So far 
the following glaciers have been selected: Lemon Creek 
Glacier in southern Alaska (near Juneau), a glacier in the 
Tindfjallajokull group in southern Iceland, Stor Glacier 
in Jotunheim in southern Norway, and Stor Glacier in the 
Kebnekajse Massif, northern Swedish Lapland. If possible 
we want to include a glacier in northernmost Greenland. 
The investigations and measurements are planned to be 
of the same kind as those of Stor Glacier in Kebnekajse. 

Improved statistical methods of analysis will eventually 
provide a more assured and detailed picture of long-range 
climatic fluctuations. New methods of age determina- 

[42] 




1*1. I A Karsa Glacier, south ot Abisko Toinisi Station in Swedish Lapland 
(68 so'N.). Photo C. C. Walk'n. it)|S. 

PI. I B Stor Glacier, Kcbnekajse Massif, Swedish Lapland (675o'N., 2117 
meters above sea level). In the background the highest elevation, Sycltopp, 
covered by a small glacier. Photo G. Lundquist, August, 1951. 




PI. II ABukkho Glacier, Jotunheim, Norway (61 4(>'N.), 19-19. The dotted 
line shows the glacier extension in about 1750. Photo O. Liestol, 1919. 

PI. II B Engabre Glacier, an outlet glacier from the Svartiscn glacier cap, 
Not way (66 [o'), in 1919; in 1930 the glacier still covered most of the lake. 




1*1. Ill A Twenty-ihice xear old and \ounger pines in the mountain biuli 
forest at Fnontekio in Finland (68 $o'N.). Photo h\ P. Mikola. if) 19. 

1*1. Ill 11 A mature pals (tailed rust in hel.md), in a flti soutli ol llofsjokull 
Iceland (6.4 <jo'N.); it is (mo in. .ihoM 1 sea lex el. 10 in. long, and neailx ij in. 
high. Photo by F. (iudinnnd.s.son, 1*151. 




PI. IV A Timber line on 
Lapland (68 2o'N.). in 1937; 



the eastern slope oi Njulja, Abisko, 
) in 19*8. Photo G. Sandberg. 



Swedish 



tion, notably by radiocarbon content, will in conjunction 
with continued paleobotanical research throw a new and 
stronger light on the climatic changes of the past thirty 
thousand years. The results of the Swedish Oceanographic 
Expedition of 1947-1948 promise to be of great impor- 
tance to our understanding of the same phenomena 
throughout a much longer period of the world's history. 
I have claimed your attention in order to sum up some 
of my thoughts on the state of our knowledge of snow, ice, 
and climate in selected areas of the world, as well as some 
scattered features of changes in the flora and fauna due to 
the present climatic fluctuation. I have done so not only 
because an account ought to be given of our observations 
and results, even though the conclusions may soon be out- 
of-date, but also and of greater moment for this gathering 
to direct your attention to the many relevant problems, 
and to stimulate continued work towards their solution 
by the newer and better methods which this constantly 
developing science brings forth. For climate, its changes 
and fluctuations, is, as Isaiah Bowman has said, a funda- 
mental factor in physical geography and one of the most 
important influences on the phenomena to which human 
geography is devoting its attention. 



[43] 



FOOTNOTES 

1 Isaiah Bowman: Geography in the Creative Experiment, Geogr. Rev., Vol. 28, 

^S 8 * PP- 1 ~ 1 9- 

2 G. M. Wrigley: Isaiah Bowman, Geogr. Rev., Vol. 41, 1951, pp. 7-65. 

3 H. W:son Ahlmann: The Contribution of Polar Expeditions to the Science 
of Glaciology, Polar Record, Vol. 5, 1949, pp. 324-331. 

4 The results of Expeditions Polaires Franchises (Missions Paul-mile 
Victor), in Publications preliminaries (mimeographed) and in Resultats sci- 
entifiques (Actualit^s scientifiques et industrielles, Hermann et Cie, Paris). 

s Popular narratives of the expedition are: John Giaever: Maudhcim: To 
ar i Antarktis Oslo, 1952); John Giaever och Valter Schytt: Antarktisboken: 
Med Norsel till Maudheim och Antarktis (Stockholm, 1952). English and 
American editions will follow. Preliminary scientific reports are: E. F. Roots: 
The Norwegian-British-Swedish Expedition 1949-52, Science News, No. 26, 
Penguin Books, 1952, pp. 9-32; G. de Q. Robin: Measurements of Ice Thickness 
in Dronning Maud Land, Antarctica, Nature, Vol. 171, 1953, pp. 55-58; The 
Norwegian-British-Swedish Antarctic Expedition, 1949-52. I. Valter Schytt: 
Summary of the Glaciological Work; II. G. de Q. Robin: Summary of Seismic 
Shooting Investigations in Dronning Maud Land, Journ. of Glaciol, Vol. 2, 
No. 13, 1953, pp. 204-205; 205-213. 

6 Quoted in a debate at the Seventeenth International Geographical Congress 
in Washington, D. C., August, 1952, in "Premiers Enseignements Glaciologiques 
des Expeditions Polaires Franchises 1948-1951." 

7 H. W:son Ahlmann: Glaciological Research on the North Atlantic Coasts, 
Royal Geogr. Soc. Research Ser. No. i, 1948, reference on pp. 66-67; idem: 
The Contribution of Polar Expeditions, op. cit., p. 327. 

8 R. P. Sharp: Accumulation and Ablation on the Seward-Malaspina Glacier 
System, Canada-Alaska, Bull. Geol. Soc. of America, Vol. 62, 1951, pp. 725-743. 

9 H. U. Sverdrup: The Scientific Results of the Norwegian-Swedish Spits- 
bergen Expedition in 1934, Part IV, The Ablation on Isachsen's Plateau and 
on the Fourteenth of July Glacier in Relation to Radiation and Meteorological 
Conditions, Geografiska Annaler, Vol. 17, 1935, pp. 145-166. 

10 C. C. Walle*n: Glacial-Meteorological Investigations on the Karsa Glacier 
in Swedish Lappland 1942-48, Geografiska Annaler, Vol. 30, 1948, pp. 451-672. 

11 Idem: Influences Affecting Glacier Extension in Northern Sweden, Union 
Gdodesique et Gdophysique Internationale, Assoc. Internatl. d'Hydrologie Sci., 
Assemble Ge'n. de Bruxelles 1951, Vol. i, Louvam, 1952. 

"H. W:son Ahlmann and Sigurdur Thorarinsson: Vatnajokull: Scientific 
Results of the Swedish-Icelandic Investigations 1936-37-38, Chapter V, The 
Ablation, Geografiska Annaler, Vol. 20, 1938, pp. 171-233 (see also the Geogr. 
Rev., Vol. 28, 1938, pp. 412-438); H. W:son Ahlmann: Vatnajokull, Ch. VII, 
The Regime of HofFellsjokull, Geografiska Annaler, Vol. 21, 1939, pp. 171-188. 

*3 B0rge Fristrup: Climate and Glaciology of Peary Land, North Greenland, 
Union Ge'odesique et Geophysique Internationale, Assoc. Internatl. d'Hydro- 



[44] 



logie Sci.j Assemblee Gen. de Bruxelles 1951, Vol. i, Louvain, 1952; idem: 
Danish Expedition to Peary Land, 1947-1950, Geogr. Rev., Vol. 42, 1952, pp. 

87-97- 

J 4 H. W:son Ahlmann: Scientific Results of the Swedish-Norwegian Arctic 
Expedition in the Summer of 1931, Part VIII, Glaciology, Geografiska Annaler, 
Vol. 15, 1933, pp. 161-216 and 261-295, reference on pp. 181-186 (Marginal 
Movements in the Spitsbergen Glaciers); idem: Scientific Results of the Nor- 
wegian-Swedish Spitsbergen Expedition in 1934, Part V, The Fourteenth of 
July Glacier, ibid., Vol. 17, 1935, pp. 167-218. 

J 5 E. F. Roots, op. cit. 

*6p. D. Baird: The Glaciological Studies of the Baffin Island Expedition, 
1950, Part I, Method of Nourishment of the Barnes Ice Cap, Journ. of Glacial., 
Vol. 2, No. 11, 1952, pp. 2-9. 

!7 F. E. Matthes: Glaciers in Hydrology, Physics of the Earth IX, New York, 
1942, pp. 149-219. 

18 Scientific Investigations in the Kebnekajse Massif, Swedish Lappland, Parts 
I-IV published to date, Geografiska Annaler, Vol. 33, 1951, pp. 90-143. Pre- 
liminary reports are: Valter Schytt: Glaciologiska arbeten i Kebnekajse, Ymer, 
Vol. 67, i9t7 pp. 18-42; H. Wrson Ahlmann: Kebnekajse, Svenska Turist- 
foreningens Arsskrift 7952, Stockholm, 1952, pp. 265-288. 

*9 W. O. Field, Jr. and M. M. Miller: The Juneau Ice Field Research Project, 
Geogr. Rev., Vol. jo, 1950, pp. 179-190; M. M. Miller and W. O. Field: Explor- 
ing the Juneau Ice Cap, Research Reviews, Office of Naval Research, Dcpt. of 
the Navy, Washington, D. C., April, 1951; R. P. Sharp, of), cit. Progress Report, 
Juneau Ice Field Research Project, Alaska, 1952. Prepared by A. K. Gilkey with 
Summaries of Research Work by Members of the Project (mimeographed). 
Amor. Gcogr. Soc., January, 1953. 

* Erik Woxnerud: Scientific Investigations in the Kebnekajse Massif, Part 
IV, Det lokala triangelnatets i Kebnekajse ansluning till riksnatet. Syd- och 
Nordtopparnas hojd over havct (The linking up of the local triangulation net 
in the Tarfala Valley with the official geodetic net. The heights above sea level 
of the Sydtopp and the Nordtopp), Geografiska Annaler, Vol. 33, 1951, pp. 
131-143. 

21 The Swedish curve is plotted by E. Bergstrom, Stockholm, on the basis 
of his studies in the Swedish glacier districts and of his comparative studies in 
Norway. Of great importance to his chronology has been the identification of 
three different zones of vegetation cover, which arc represented especially by 
lichens. The boundary of each zone appears to correspond to the position of 
the ice margin at a time when the glacier extended as far as one of the principal 
old terminal moraines. 

The Norwegian curve relates to the Nigardsbre, an outlet glacier from 
Jostedalsbre, which may be regarded as being representative of the glaciers 
of southern Norway. The values are plotted by O. Liestol, of the Norwegian 
Polar Institute, from Knut Faegri: Ober die Langenvariationen einiger Glet- 
scher des Jostedalsbre und die dadurch bedingtcn Pflanzensukzessionen, Bergens 

[45] 



Museums Arbok 1933, Naturvidenskapelig rekke, No. 7, Bergen, 1934; idem: 
On the Variations of Western Norwegian Glaciers During the Last 200 Years, 
Procds-Verbaux des seances de I'AssembUe Gen. d'Oslo de I'Union Geodesique 
et Geophysique Internationale, Louvain, 1948; and from consecutive measure- 
ments carried out by the Norwegian Polar Institute, Oslo. 

22 The Drangajokull. curve is based upon Jon Eyth6rsson: On the Variations 
of Glaciers in Iceland, I, Drangajokull, Geografiska Annaler, Vol. 17, 1935, pp. 
121-136, and for later years on Eythorsson's measurement of four outlet glaciers 
from the ice cap, plotted together by Sigurdur Thorarinsson. The Vatnajokull 
curve is based upon Eythorsson's measurements of about 18 of the southern 
outlet glaciers on the ice cap, summarized to the year 1930, by Thorarinsson in 
Vatnajokull, Chapter XI, Oscillations of the Iceland Glaciers in the Last 250 
Years, ibid., Vol. 25, 1943, pp. i~54, and after that year supplemented by him. 

23 M. Mougin: Glacier des Bossons, tudes glaciologiques en Savoie in tudes 
glaciologiques, Service des Forces Hydrauliques, Vol. 3, Paris, 1912, and Vol. 
5, Paris, 1925; and Rapport sur les variations de longeur des glaciers de 1913 
a 1928, Commission des glaciers, Union Ge"ode"sique et Geophysique Interna- 
tionale, Venice, 1930. After 1925 there are sporadic measurements published in 
Commission des glaciers, U.G.G.I. They are, however, sufficient to allow plotting 
of the dashed part of the curve. The rapid recession of the last few years 
parallels conditions in other parts of the Alps. The curve is plotted by O. 
Liestol, Oslo. 

24 Plotted by the author from: D. B. Lawrence: Glacier Fluctuation for Six 
Centuries in Southeastern Alaska and Its Relation to Solar Activity, Geogr. Rev., 
Vol. 40, 1950, pp. 191-223; idem: Glacier Fluctuation in Northwestern North 
America during the Past Six Centuries. Proce's-Verbaux des seances de I' As- 
semblee Gen. d'Oslo de I'Union Geodesique et Geophysique Internationale, 
Louvain, 1948; and from H. W. Mathews: Historic and Prehistoric Fluctua- 
tions of Alpine Glaciers in the Mount Garibaldi Map-Area, Southwestern 
British Columbia, Journ. of GeoL, Vol. 59, 1951, pp. 357-380. 

25 Ad. S. Jensen and B0rge Fristrup: Den arktiske klimaforandring og dens 
betydning, sacrlig for Gr0nland, Geogr. Tidskrift, Vol. 50, 1950, pp. 20-47 (see 
also W. R. B. Battle: Contributions to the Glaciology of North East Greenland 
194849 in Tyrolerdal and on Clavering 0, Meddelelser om Gr0nland, Vol. 
136, No. 2, 1952, pp. 1-26 (second section). 

26 H. W:son Ahlmann: Studies in North-East Greenland, 1939-40, Part II, 
Glacial Conditions in North-East Greenland in General and on Clavering 
Island in Particular, Geografiska Annaler, Vol. 23, 1941, pp. 183-209. For 
observations in 1947, see Ad. S. Jensen and B0rge Fristrup, op. cit. Charles 
Swithinbank carried out investigations here during the Norwegian Polarbjorn 
expedition, 1952. 

27 p. D. Baird: The Baffin Island Expedition, 1950, Geogr. Journ., Vol. 118, 
1952, pp. 267-279. 

28 See also Sigurdur Thorarinsson: Vatnajokull, Chapter XI, op. cit., and 
"1 veldi Vatnajokuls," I in Lesb6k Morgunblathsins 1946, Reykjavik, 1946. 



[46] 



2 9 Rapport sur les variations de longeur de glaciers europ6ens de 1947 a 1950, 
Union Geodesique et Geophysique Internationale, Assoc. Internatl. d'Hydro- 
logie Sci., Assemblee Gen. de Bruxelles 1951, Vol. i, Louvain, 1952. 

30 A review of these oscillations up to 1940 is given by F. E. Matthes, op. cit.; 
A. E. Harrison: Ice Advance during the Recession of the Nisqually Glacier, 
Mountaineer, Vol. 43, Dec., 1951, pp. 7-12. 

31 D. B. Lawrence, op. cit.; J. L. Dyson: Glaciers of the American Rocky 
Mountains, Triennial Report, Committee on Glaciers, Section of Hydrology, 
American Geophysical Union (mimeographed), 1952. See also C. J. Heusser: 
Pollen Profiles from Southeastern Alaska, Ecological Monographs, Vol. 22, 

!952, pp- 33!-352- 

32 W. O. Field, Jr.: Glacier Recession in Muir Inlet, Glacier Bay, Alaska, 
Geogr. Rev., Vol. 37, 1947, pp. 369-399. 

33 See also R. L. Nichols and M. M. Miller: The Moreno Glacier, Lago 
Argentino, Patagonia, Journ. of Glaciol., Vol. 2, No. 11, 1952, pp. 41-50. 

34 See also P. D. Baird: Report on the Northern American Glaciers, Union 
Geodesique et Geophysique Internationale, Assoc. Internatl. d'Hydrologie Sci., 
Assemblee Gen. de Bruxelles 1951, Vol. i, Louvain, 1952. A. E. Harrison (per- 
sonal communication) says that "the terrific recession characteristic of the 
twenties and thirties seems to have passed a climax." 

35 A. E. Harrison: Ice Advance, op. cit., and Glacier Studies 1952 Sequel, 
Mountaineer, Vol. 44, 1952. In the latter he points out: 'In spite of two seasons 
of excessive melting and the loss of ice at the higher elevations on the glacier, 
the wave of ice reported last year (1951) is still making progress down the 
Nisqually Glacier. The accumulation of ice since 1944 is too great to be dissi- 
pated immediately." See also R. A. Dightman and M. E. Beatty: Recent 
Montana Glacier and Climate Trends, Monthly Weather Rev., Vol. 80, 1952, 
pp. 77-81. 

3<5Sigurdur Thorarinsson: Present Glacier Shrinkage, and Eustatic Changes 
of Sea-Level, Geografiska Annaler, Vol. 22, 1940, pp. 131-159. See also, for 
instance, L. C. W. Bonacina and E. L. Hawkes: Climatic Change and the 
Retreat of Glaciers (with discussion), Quart. Journ. Royal Metcorol. Soc., Vol. 
37, 19^7, pp. 85-95; R- F- Flin^ Climatic Implications of Glacier Research in 
Compendium of Meteorology, edited by T. F. Malone (Amer. Meteorol. Soc., 
Boston, 1951), pp. 1019-1023. 

37 J. de Heinzelin: Glacier Recession and Pcriglacial Phenomena in the 
Ruwenzori Range (Belgian Congo), Journ. of Glaciol., Vol. 2, London, 1952, 
pp. 137-140. (This issue also contains references to articles about other African 
mountains which support glaciers.); E. Bergstrom: Som glaciolog p Ruvenzori 
(As Glaciologist on Ruwenzori, with an English Summary), Ymer, Vol. 73, 1953, 
pp. 1-23. 

38 Sirri Erinc.: Glacial Evidences of the Climatic Variations in Turkey, Geo- 
grafiska Annaler, Vol. 34, 1952, pp. 89-98. 

39 There is, however, "no proof of a general recession of south Patagonian 
glaciers during the last twenty years" (Louis Lliboutry: More About Advancing 

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and Retreating Glaciers in Patagonia, Journ. of GlacioL, Vol. 2, No. 13, 1953, 
pp. 168-172; reference on p. 172). 

40 H. J. Harrington: Glacier Wasting and Retreat in the Southern Alps of 
New Zealand, Journ. of GlacioL, Vol. 2, 1952, pp. 140-145. 

41 Leo Lysgaard: Recent Climatic Fluctuations, Folia Geographica Danica, 
Vol. 5, 1949 (with extensive bibliography); H. C. Willett: Temperature Trends 
of the Past Century, Centenary Proc. Royal Meteorol. Soc., 1950, pp. 195-206. 

Among numerous other studies of the present climatic fluctuation, the follow- 
ing may be mentioned: 

Anders Angstrom: Teleconnections of Climatic Changes in Present Time, 
Geografiska Annaler, Vol. 17, 1935, pp. 242-258. 

Idem: The Change of the Temperature Climate in Present Time, ibid, Vol. 

21. 1939' PP- H9-13 1 - 
Idem: Nederbordsklimatets andring i nuvarande tid, Stat. Mct.-Hydro. An- 

stall, Meddelandcn, Serien uppsatscr, No. 37, Stockholm, 19 |i. 

II. W:son Ahlmann: Den nutida klimatfluktuationen, Ymcr, Vol. 61, 191 1, 
pp. 11-24. 

Idem: Den nutida klimatfluktuationen och Gronland, Del Gr0nlandske 
Selskabs Aarsskrift, 1947, pp. 9-38. 

Idem: The Present Climatic Fluctuation, Gcogr. Journ., Vol. 112, 1949, pp. 

165-195- 

B. E. Eriksson: Till kannedomen orn den nutida klimatandringcn inom 
omradena kring nordligaste Atlanten, Geografiska Annaler, Vol. 25, 1913, pp. 
170-201. 

J6n Eythorsson: Temperature Variations in Iceland, Geograjnka Annaler, 
Vol. 31, 1949, pp. 36-55. 

Th. Hesselberg and B. J. Birkeland: Siikulare Schwankungen des Klimas von 
Norwegen, Geofysiske Publikasjoner, Vol. 14, Nos. 4-6, Oslo, 1940-1913, and 
Vol. 15, No. 2, 1944. 

J. Keranen: Uber die Temperaturschwankungen in Finland und Nordcuropa 
in den letzten hundert Jahren, Finn. Akad. der Wissensch., Sitiungsber., IQJI, 

1944- 

J. B. Kincer: Is Our Climate Changing? A Study of Long-Time Temperature 
Trends, Monthly Weather Rev., Vol. 61, 1933, pp. 251-259. 

Idem: Our Changing Climate, Trans. Amer. Geophys. Union, Vol. 27, 1946, 
PP- 342-347- 

A. Labrijn: Het klimaat van Nederland gedurende de laatste twee en een 
halve eeuw (With an English summary), Mededeling en Verhandelingen, 
Koninkl. Nederl. Meteorol. Imt., Vol. 49, No. 102, Gravcnhage, 1945. 

H. Landsberg: Climatic Trends in the Series of Temperature Observations 
at New Haven, Conn., Geografiska Annaler, Vol. 31, 1949, pp. 125-132. 

Idem: Some Recent Climatic Changes in Washington, D. C., Archiv fur 
Meteorologie Geophysik und Bioklimatologie, Ser. B., Vol. 3, Vienna, 1951, 
pp. 65-71. 

[48] 



L. B. Leopold: Rainfall Frequency: An Aspect of Climatic Variation, Trans. 
Amer. Geophys. Union, Vol. 32, 1951, pp. 347-357. 

G. H. Liljcquist: The Severity of the Winters at Stockholm 1757-1942, 
Geografuka Annaler, Vol. 25, 1943, pp. 81-101. 

Idem: On Fluctuations of the Summer Mean Temperature in Sweden, ibid., 
Vol. 31, 1919, pp. 159-178. 

Gordon Manlcy: Temperature Trend in Lancashire, 1753-1945, Quart, Journ. 
Royal Meteorol. Soc., Vol. 72, 1946, pp. 1-31. 

Idem: The Range of Variation of the British Climate, Geogr. Journ., Vol. 
117, 1951, pp. 43-68. 

Idem: The Mean Temperature of Cential England, 1698-1952, Quart. Journ. 
Royal Meteorol. So( ., Vol. 79, 1953. 

Idem: Climatic Variation, ibid., pp. 185-209. [Note the bibliographical 



Sverre Petteisseu: Changes in the General Circulation Associated with the 
Recent Climatic Variation. Gcografiska Annaler. Vol. 31, 1949, pp. 212-221. 

F. Piohaska: /in Frage der Klimaandc-rung in Polar/one des Sudatlantiks, 
Arcliiv fur Meteoiologie Gcophystk ujid Biokltmatologie, Ser. B., Vol. 3, Vienna, 

'OS 1 - PP- 7-- 81 - 

Mat tin Rodewald: Ruckgang dcr Klimaandeiung in den Vercinigtcn Staaten, 
Geograjiska Annaler, Vol. 34. 1952, pp. 159-167. 

E. Rubenstein: K piobleme i/minenija klimata, Ser. Hydjo-Meteorol. Serv- 
ice. Sci. Research Dept., Geophys. Centre, Leningrad, 1946. 

R Scherhag: Fine bemcrkenswertc Klimaandcrung uber Nordeuropa, An- 
nalen der Hydrogr. und Alarit. Meteorol.. Vol. 64, 1936, pp. 96-100. 

Idem: Die Fiwarinung des Nordlichcn Polargebiets, ibid.. Vol. 67, 1939, pp. 

57- ( i7- 

A. Wagner: Klimaandcrungen und Klimaschwankungcn, Die Wissenschaft, 
Vol. 92, Brunswick, ig.jo. 

H. Winter: Anderungen im Sommerklima scit 150 Jahren. Archiv fur 
Mt'tcorologie Geophysik und Bioklitnatologie, Scr. B., Vol. 3, Vienna, 1951, pp. 
82-90. 

^A. Labrijn: Ondcr/oek naar Klimaatschommelingcn in het Stroomgebied 
van de Rijn, Mededeling van het Hedrijf der Gemeentewaterleidingen, No. 10, 
De Watervoor/iening van Amsterdam, Aanvullende Gegevens op Rapport, 

i91. 

43 Mart in Rodewald, op. cit. 

44 H. W:son Ahlmann: Glaciological Research, op. cit., pp. 77-78. 

45 A. Wagner: Untersuchungrn der Schwankingcn der allgcmcine Zirkulation, 
Geografiska Annaler, vol. 11. 1929, pp. 33-82. 

46 B. E. Eriksson, op. cit. 

47 H. W. Willctt: Descriptive Meteorology, New York, 1944; idem: Long- 
period Fluctuations in the General Circulation of the Atmosphere, Journ. of 
MeteoroL, Vol. 6, 19-19. pp. 34-50. 

48 Sverre Pctterssen, Changes in the General Circulation, op. cit. 



[49] 



49 C. C. Walln: Recent Variations in the General Circulation As Related to 
Glacier Retreat in Northern Scandinavia, Geofisica Pur a e Applicata, Vol. 18, 
Milan, 1950, pp. 3-6; idem: Glacial- Meterological Investigations, op. cit.; 
idem: Influences, op. cit. 

so G. H. Liljequist: On Fluctuations of the Summer Mean Temperature, 
op. cit. 

51 Influences, op. cit. 

52 D. F. Rex: Blocking Action in the Middle Troposphere and Its Effect Upon 
Regional Climate, Tellus, Vol. 2, 1950, pp. 196-211 and 275-301; Vol. 3, 1951, 
pp. 3-16. 

53 Sverre Petterssen: Some Aspects of the General Circulation of the Atmos- 
phere, Centenary Proc. Royal Meteorol. Soc., 1950, pp. 120-155. 

54 C. E. P. Brooks: Climate Through the Ages (rev. edit., London, 1949). 

55 Ad. S. Jensen and B0rge Fristrup: Den Arktiske klimaforandring, op. cit. 

56 Hans Hedtoft: Gr0nlands Fremtid, Det Gr0nlandske Selskabs Aarsskrift, 

1949, pp. 22-42. In a lecture at Oslo in February, 1953, Director P. Rosendahl 
of the Greenland State Department in Copenhagen pointed out that the 
principal reason for the new era in Greenland has been the present climatic 
fluctuation with the associated disappearance of the seals and the northern 
migration of cod. 

57 H. W:son Ahlmann: The Present Climatic Fluctuation, op. cit., p. 192. 

58 The Recent Climatic Fluctuation in Finland and Its Consequences, Fennia, 
Vol. 75, Helsinki, 1952. 

59 In an unpublished article C. C. Wallen has shown that from the period 
18831913 to 1930-50 the temperature of the surface water in the Gulf of 
Bothnia rose as much as 2 C. in August, and little less in other months. A 
warming up of the water has also taken place in the southern part of the 
Baltic as well as on the west coast of Sweden. 

60 G. Sandberg: Den pagaende klimatforandringen, Svenska Vall-och Mosskul- 
turforeningens Kvartalsskrift 1940, Uppsala, 1940; and his report to the author 
dated July, 1952. 

61 F. Bergsten: Contribution to Study of Evaporation in Sweden, Sveriges 
Meteorol. o. Hydrol. Inst., Meddelanden Ser. D., Nr. 3, 1950. 

62 S. Ve: Stig skoggrensa? Tidskrift for Skobruk, No. 9, Oslo, 1951, pp. 305- 

317- 

63 Sigurdur Thorarinsson: Notes on Patterned Ground in Iceland, with 
Particular Reference to the Icelandic "Flas," Geografiska Annaler, Vol. 33, 1951, 

pp. 144-15 6 - 

6 4 R. F. Black and W. L. Barksdale: Oriented Lakes of Northern Alaska, 
Journ. of GeoL, Vol. 57, 1949, pp. 105-1 18. 

6 5 Finnur Gudmundsson: The Effect of the Recent Climatic Changes on the 
Bird Life of Iceland, Proc. loth Internatl. Ornithological Congress, Uppsala 

1950, Stockholm, 1951, pp. 502-514. 

66 Plotted by E. Bergstrom. Before 1650 A.D. based principally on: F.A.D. 
Enquist: Die glaciale Entwicklungsgeschichte Nordwestskandinaviens, Sveriges 
GeoL Undersokning, Ser. C., Nr. 285, 1918. After 1650 A.D. on: Knut Faegri: 



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On the Variations of Western Norwegian Glaciers During the Last 200 Years, 
Proces-Verbaux des seances de I'Assemblee Gen. d'Oslo de ['Union Geodesique et 
Geophysique Internationale, Louvain, 1948; Axel Hamburg: Sarjekfj alien, 
Yrner, Vol. 21, 1901, pp. 145-204 and 223-276; N. H. Magnusson, E. Granlund, 
and G. Lundqvist: Sveriges geologi, 1949; A. Wagner: Klimaiinderungen und 
Klimaschwankungen, op. cit.; A. Walle"n: Om langvariga klimatforandringar 
och kallorna for deras utforskande, Popular Naturvetenskaplig Revy, Vol. 6, 
Stockholm, 1918; Anders Angstrom: Sveriges kliinat, Generalstabens litografiska 
Anstalt, 1946. 

6 7 Plotted by O. Licstol, Oslo. Bases: J. B. Rekstad: Skoggnensens og sneliniens 
st0rrc h0itle tidligere i det sydlige Norge, Norges Geologiske Under so gelse, 
Aarbog for 1903, Vol. 36, No. 5; Knut Faegri: Ober die Langenvariationen 
einigcr Glctschcr dcs Jostedalsbre, Bergens Museums Arbok 1933, Naturviden- 
skapelig rekke, No. 7; idem: Quartargeologische Untersuchungen im westlichen 
Norwegen, I-II, Bergens Museums Arbok, Heft 3, No. 8, 1935, and Heft 2, 
No. 7, 1910; Erik Granlund: De svcnska hogmossarnas geologi, Sveriges Geol. 
Unders. Ser. C., No. 373, Arsbok, Vol. 26, No. i, 1932. 

68 Jon Eythorsson: Tliykkt Vatnajokuls, Jokull, Joklarannsoknafelag Islands, 
Vol. i, Reykjavik, 1951. 

<*>> Sigurdur Thorarinsson: The Thousand Years' Struggle Against Ice and 
Fire (Special University Lecture, Bedford College, London University, February, 



7<> H. W:son Ahlmann: The Present Climatic Fluctuation, op. cit., p. 166. 
P. N0rlund: De gamle Nordbobygder vcd Vcrdcns Ende, Copenhagen, 1934; 
J. Iverscn: Nordboernes Undergang paa Gr0nland i geologisk Belysning, Gron- 
landske Selskabs Aarsskrift, 1034-35, 1935. 

71 P. N0ilund: Buried Norsemen at Herjolfsnes: An Archeological and 
Historical Study, Meddelelser om Gr0nland, Vol. 67, 1924, pp. 1-270 (see the 
abstract by William Hovgaard: The Norsemen in Greenland, Geogr. Rev., Vol. 
15, 1925, pp. 605-616); Lauge Koch: The East Greenland Ice, Meddelelser om 
Gr0nland,Vo\. 130, 1915. 

72 H. W:son Ahlmann: The Present Climatic Fluctuation, op. cit., p. 166 

73 H. Kinzl: Die grossten nacheiszeitlichen Gletschervorstosse in den Schweizer 
Alpcn und in der Mont Blanc-Gruppc, Zeitschrift flir Gletscherkunde, Vol. 20, 
JOS 2 ' PP- 269-397. 

74 F. E. Matthes: Glaciers, op. cit., p. 207. 

75 Sigurdur Thorarinsson: Some Tephrochronological Contributions to the 
Volcanology and Glaciology of Iceland, Geografiska Annaler, Vol. 31, 1949, pp. 
239-256. See also E. M. Todtmann: Im Gletscherruckzugsgebiet des Vatna 
Jokull auf Island, Neues Jahrb. Geol. und Palciontologie, Nov. 1951, Stuttgart, 

95 l - 

76 H. W:son Ahlmann: Glaciers in Jotunheim and their Physiography, 
Geografiska Annaler, Vol. 4, 1922, pp. 1-57. 

77 Leo Aario: Ein nachwarmezeitlicher Gletschervorstosse in Oberfernau in 
den Stubaier Alpen, Acta Geographica, Vol. 9, No. 2, Helsinki, 1944, pp. 1-31. 



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